Hello

I have an 83 944 n/a that will not start! I have used a few of the Clark's Garage Shop Manual pages to try to figure out why. I found the reference sensor was bad and wound up replacing the bracket and both sensors. I still can not get the car to fire up. I have tried the DME in another car and it works. When I go to start the best reference point is the coil. It start at 0v, turning the key to on, it changes state to 12v, then when starter is engaged is goes to 0. the Fuel pump does not go on.

Ok here is what I have tested/tried.

The reference sensor and speed sensor both ohm out good and produce pulses. ~+/- 4v on reference, ~+/- 10v on speed. Lot more pulses on the speed then reference. Measurements where checked on the DME connector. Reference on pins 26&27, Speed on 8 and 25. (I did try switching the connectors in case I did messed up.. did not help)

Fuel pump relay; When key is on I have +12v on dme pins 18 & 35. The fuel relay draw 0.15a on pin 20 to ground and the fuel pump runs. I have ohm and verify the relay. I have tried a bypass .. but since the coil does not fire that does not do any good.. pin 18 has power during when start is engaged.

I do get 12v on pin 4 when starter is engaged.

I have cleaned the connectors.

I have put the DME in my 85 944 and it works.

No alarm in car...

I assume that the DME does not like something and does not engage the fuel pump and coil.

I have search the list.. But the DME runs in the other car. the fact the Fuel pump and Coil don't run sound like it not looking for something and not finding it.

Any idea on what to test/check next....

THANKS

 

Replace the ingition switch.

 

Hello tim,

check out my post "New Rennlist member needs help". There may be something there you may find useful.

 

Rigged up a bypass around switch. Did not catch Tuesday Night or Wednesday morning. But it runs now!